Apparently it is just the slightest bit warmer on one side. It’s called the dipole of the cmb. I don’t fully understand it, but as far as I know astrophysicists don’t understand it either. ;-)
But how would you use the dipole to specify where you are? Isn’t the dipole the same everywhere? I’d think the dipole could possibly specify a fixed direction, but that’s hardly enough to specify a fixed point referencing only the CMB.
In the sense that the Cosmic Microwave Background (CMB) is visible from every point in space. No matter where you are you can determine your position relative to the CMB, making it a common reference point for the entire universe.
I understand that it is visible from all of space, but doesn’t it look the same from all points in space? Wouldn’t everyone looking at it simply conclude “I am at the center of the CMB”? How would you use it to specify a certain point?
Ah, but using the cosmic microwave background we actually can determine a universal coordinate system to fix a point in space.
that sounds like you’re relating your position to something else 😏
Oh, so that’s why Earth is spinning!
The centre is hot while the outside is cold - that’s how we know it’s true
Life is naught but a warm burrito on the rotating microwave plate of Earth.
Yeah, and some asshole thought it’d be cool to put fish in it.
But only related to the cosmic microwave background, which, while more universal than most other reference frames, is ultimately still arbitrary
North is arbitrary as well, that doesn’t mean you can’t use it for spatial referencing.
Yes, for practical purposes, absolutely! But you’re always just aligning with something else moving through space, not space itself
It can be as arbitrary as it wants it still allows you to use relative positioning to determine a fixed point.
I think they mean it would be “Stay at this exact point in the CMB rest frame” but not “in space” because the “space rest frame” is nonexistent
That’s a little wordy though, so most people would just say “in space”
Why cosmic microwave background radiation? Is that any less arbitrary than e.g. the sun?
i mean if we were to communicate with aliens in another galaxy it would be the “least arbitrary” one
Wouldn’t the conversations go like this?
Me: I’m about 2/3rds out the longest arm of my galaxy
Alien: OK
vs
Me: I’m at the place where the CMBR is evenly redshifted in all directions.
Alien: Huh, me too?
that’s not a place that’s a frame of motion (i think)
the only issue is it’s hard to define an origin for that frame, so yeah it’s not gonna be all that useful indeed
Well, it’s the only thing we know of that can be used in the whole universe.
Use it how? I’ve never heard about this, and I can’t seem to find anything about it by searching
Apparently it is just the slightest bit warmer on one side. It’s called the dipole of the cmb. I don’t fully understand it, but as far as I know astrophysicists don’t understand it either. ;-)
But how would you use the dipole to specify where you are? Isn’t the dipole the same everywhere? I’d think the dipole could possibly specify a fixed direction, but that’s hardly enough to specify a fixed point referencing only the CMB.
Huh, you’re right. I guess at a position you can use it to define a point. A point where you don’t move in any other direction.
In the sense that the Cosmic Microwave Background (CMB) is visible from every point in space. No matter where you are you can determine your position relative to the CMB, making it a common reference point for the entire universe.
I understand that it is visible from all of space, but doesn’t it look the same from all points in space? Wouldn’t everyone looking at it simply conclude “I am at the center of the CMB”? How would you use it to specify a certain point?